HP5 Overexpose / Underdevelop Question

Lachlan Young · Jan 18, 2021

And it's not necessarily the quantity of silver halide (or gelatin volumes) that defines development speed in today's factory emulsions, a lot of it's more about the available surface area to react with the developer (for example, lots of small regularly shaped crystals develop faster) - and the solvency of the developer can enable access to the bigger more difficult to develop crystals. None of this is simple or particularly linear. TMax 100 had to have an extra thick supercoat layer to slow developer diffusion because the T-grains would otherwise develop so fast as to be much less controllable than would be desirable.

138S · Jan 18, 2021

vedostuu said:
In your canadianfilmlab test there was -3 stop exposure as example and based on what you wrote that should be quite dark, I believe. But it is not.

Look, ISO speed calibration ensures that the speed point (0.1D density, plus B+F) is 3.33 stops underexposed, in the canadianfilmlab test subject is lighter than backgound, if it was incident metered the face is at +2 resulting -1 locally. The (now killed) 400H case is a bit a kown exception, metering has an influences... but a -3 (exposure compensation) underexposed shot have areas that were bright and had a lower underexposure.

vedostuu said:
I'm not saying the test is perfect, but carmencitafilmlab is a pretty known and reliable lab.

OK, but this test is is a pitfall, at -5 you have nothing. Still those bright zones that are +2 locally over the averaged metering will be locally at -3, so you get an image.

vedostuu said:
Based on your claim 4 stops underexposure should be dark. But it isn't.

The zones you point were not at -4, if spot metered would have been -3 or more exposed.

As you look interested, I would recommend you to get Beyond The Zone System book by Phil Davis, an excellent vault of knowledge about practical sensitometry.

Ilford does not provide curves but this is how all films behave:

ISO calibration places 0.1D over base+fog

radiant · Jan 18, 2021

138S said:
OK, but this test is is a pitfall, at -5 you have nothing. Still those bright zones that are +2 locally over the averaged metering will be locally at -3, so you get an image.

-5 of what?

I'm guessing carmencita has measured by incident/camera TTL and then shot frames ranging from -5 to +5 to measured exposure and they have scanned the results. And probably with a really good scanner too.

If you have wide SBR and you underexpose by -5 (from meter reading), you don't end up with completely black image. Sure your shadows and maybe some mids are destroyed, but it is not completely black because the highlights have still details.

Sirius Glass · Jan 18, 2021

michael_r said:
In a nutshell, in ISO, 0.1 above fb+fog is located 3 1/3 stops below the metered exposure, whereas in the Zone System we are told to look for it 4 stops below the metered exposure. It is therefore no surprise that most Zone System practitioners who have tested as carefully as they can, tend to come up with an EI 2/3 stop lower than the ISO speed.

The unfortunate part is you go through all the testing, just to confirm what is on the box is correct. No new information is revealed - contrary to what a lot of books and gurus say. If one wants to use the Zone System, the correct EI is simply ISO speed minus 2/3 stop, so you might as well just skip that part and move on to the expansion/contraction stuff.

Well almost to the point. The Zone System metering aids in capturing the shadow detail. With today's negative film, Zonistas are merely testing, testing, testing their life away.

138S · Jan 18, 2021

vedostuu said:
-5 of what?

I'm guessing carmencita has measured by incident/camera TTL and then shot frames ranging from -5 to +5 to measured exposure and they have scanned the results. And probably with a really good scanner too.

If you have wide SBR and you underexpose by -5 (from meter reading), you don't end up with completely black image. Sure your shadows and maybe some mids are destroyed, but it is not completely black because the highlights have still details.

Of course, if averaged metering is -5 then we may have areas at -8 and areas at -2, all averaged is -5. Those areas at -2 will be recorded. If we spot meter then we'll know what we'll record and what not.

Still, that carmencita -5 is totally inconsistent becsue all image is relatively well recorded, a pitfall should be there.

DH_Studio · Jan 18, 2021

Juan Valdenebro said:
Hello DH,
Ilford's official times don't include times for HP5+ at 200 because for normal contrast scenes that film reaches 400 in normal (MQ) developers... 200 is OK for direct sunlight scenes, though, with shorter development times...
If you used 200 under soft overcast light, anyway your negatives will be totally fine...
By the way, I use that film for overcast at 640 precisely in D-76 1+1, at 22C... That's for a Kaiser condenser enlarger, with the Nikon 50mm f/2.8, with Dektol and Ilford warmtone multigrade paper.
My times are 10% less than Ilford times.
In your case I would develop normally, as if 400 was the EI used... I see 13 minutes at 400 with Ilford agitation: 4 inversions in the beginning and 4 inversions every minute, for D-76/ID-11 1+1 at 20C...
11.5 minutes at 20C for condenser enlargers, or 14.5 minutes at 20C for diffusion enlargers should give you negatives precise enough for wet printing, using Ilford agitation...
With Kodak agitation (I do 8 fast inversions in the beginning and 4 fast inversions every 30 seconds 'cause I use D-76) times become shorter...
D-76 and ID-11 are basically the same developer: just take into account if you'll use Ilford or Kodak agitation. Current D-76 works very well with fast inversions, as recommended by Kodak.
So, depending on your enlarger, your enlarging lens, the scene contrast, and depending also on the type of agitation used, only you can find what's optimal for your equipment, in the range of 8 to 12 minutes, now you exposed at EI200.
As you see, not an easy fast answer.

Thank you for that detailed response, Juan! I'm pretty new to this so it really helps! I didn't realize agitation had such an impact on development times.

DH_Studio · Jan 18, 2021

Old Gregg said:
I am guilty of not shooting enough, and spending way too much time on photo forums, and I have never heard of this. Maybe you're confusing it with people often saying that HP5+ is "flat", but that has nothing to do with density.

When trying a new developer, I always start with the times in Ilford's data sheet and never saw thin negatives. Actually, quite the opposite: Ilford's times are calculated for Ilford's agitation routine (once a minute) and if you're agitating Kodak-style (30 seconds) you end up with more density, not less.

Easy now, fuzzy little man peach.

Dude.

A: thanks for the info.

But most importantly, B: BEST USER NAME ON PHOTRIO.

radiant · Jan 18, 2021

138S said:
Still, that carmencita -5 is totally inconsistent becsue all image is relatively well recorded, a pitfall should be there.

Could it be that they have scanned the film with a good scanner? Their webpage mentions NORITSU HS-1800 as one of their scanners. Could that pull out more information from shadows?

DH_Studio · Jan 18, 2021

Andrew O'Neill said:
So, what did you end up doing?

I'm processing today. I shot some pretty contrasty scenes in bright sun, going to give 9 minutes a try in 1+1 D76. Will report back. Thank you!

DH_Studio · Jan 18, 2021

Lachlan Young said:
About 9-10 min, 1+1, 20oC is often a good place for EI 200 HP5+ in ID-11/ D-76.

Thanks Lachlan!

138S · Jan 18, 2021

vedostuu said:
Could it be that they have scanned the film with a good scanner? Their webpage mentions NORITSU HS-1800 as one of their scanners. Could that pull out more information from shadows?

I don't think... under -3.5 halide crystals are simply not exposed, a crystal needs to receive 2 or 3 photons in time to get electronically marked (electron lost), if the crystals are not electronically marked they simply won't develop an image.

ISO calibration takes uses point where film starts being exposed (speed point), and meters aim 3.33 stops more lights, which is x10 more light. With ISO well selected in the meter, the meter instructs you adjust x10 more more exposure (in Lux·second) that the required in the speed to start exposing film.

So under -3.33 (spot metered) expect nothing worth.

DH_Studio · Jan 18, 2021

Old Gregg said:
Haha, so happy to see someone recognize the greatest TV show ever made.

The call me The Genre Spanner.

zanxion72 · Jan 19, 2021

Old Gregg said:
I am guilty of not shooting enough, and spending way too much time on photo forums, and I have never heard of this. Maybe you're confusing it with people often saying that HP5+ is "flat", but that has nothing to do with density.

When trying a new developer, I always start with the times in Ilford's data sheet and never saw thin negatives. Actually, quite the opposite: Ilford's times are calculated for Ilford's agitation routine (once a minute) and if you're agitating Kodak-style (30 seconds) you end up with more density, not less.

I am not confusing anything my friend. The given time for HP5 gives a rather thin film negative. I have tested that film to more developers you can think of (135 and Medium Format only), commercial and home brew.My preferred rating, if you don't like the term true speed, in ID11/D76 is EI 320 and EI 200 is not far from it.
Btw, my preferred normal agitation scheme is 5 inversions/rotations (lasting 10") every minute. I never liked the results of Kodak's suggested agitation scheme.

138S · Jan 19, 2021

zanxion72 said:
I am not confusing anything my friend. The given time for HP5 gives a rather thin film negative. I have tested that film to more developers you can think of (135 and Medium Format only), commercial and home brew.My preferred rating, if you don't like the term true speed, in ID11/D76 is EI 320 and EI 200 is not far from it.
Btw, my preferred normal agitation scheme is 5 inversions/rotations (lasting 10") every minute. I never liked the results of Kodak's suggested agitation scheme.

From ISO 400 to EI 320 we have around 1/3 stop less diference. 400-320= 80... and 80 is 20% of 400 . In practice this is irrelevant. Using HC-110 vs Xtol decreases that.

Also, how fresh the film is? Just manufactured or it was in the bottom of a big box and it was sold 6 month later ? Did you keep it 6 months outside freezer?

What meter do you use ? 1/6 of stop is an easy mismatch... Spectral light nature? What kind of light ? How do you meter ? people meter 1 stop differently...

With today's norms one can use any developer to make a calibration, if not telling the developer true speed calculation make no sense beyond 1/2 stop.

To know if we use an ISO standard development (to find true speed) it should result a 0.17D density increase for each addiional stop, so your negatives are in the thin side if an additional stop exposuse increases density by less than 0.17D. (beyond linearization)

In that situation (0.17D per stop) we may investigate if we are using the "true speed", ("gray") spots metered at -3.33 should have 0.1D more than Base+Fog if we use the True Speed of Film+Developer.

Box speed nicely tells the film nature, but no film is ISO 400, it can be ISO 379.23 or 404.42, speeds are rounded to a comercial standard values (norm allows that), there is a manufacturing variability, we have film aging, and or course we have very different ways to meter that can easily differ 1 stop.

zanxion72 · Jan 19, 2021

138S said:
From ISO 400 to EI 320 we have 1/3 stop diference. 400-320= 80... and 80 is 20% of 400 . In practice this is irrelevant. Using Xtol vs HC-110 decreases that.

Also, how fresh the film is? Just manufactured or it was in the bottom of a big box and it was sold 6 month later ? Did you keep 6 months outside freezer?

What meter do you use ? 1/6 of stop is an easy mismatch... Spectral light nature? What kind of light ? How do you meter ? people meter 1 stop differently...

With todays's norms one can use any developer to make a calibration, if not telling the developer true speed calue make no sense beyond 1/2 stop.

To know if we use an ISO standard development (to find true speed) it should result a 0.17D density increase for each addiional stop, so your negatives are in the thin side if an additional stop exposuse increases density by less than 0.17D. (beyond linearization)

In that situation (0.17D per stop) we may investigate if we are using the "true speed", ("gray") spots metered at -3.33 should have 0.1D more than Base+Fog if we use the True Speed of Film+Developer.

Box speed nicely tells the film nature, but no film is ISO 400, it can be ISO 379.23 or 404.42, speeds are rounded to a commercial standard values (norm allows that), there is a manufacturing variability, we have film aging, and or course we have very different ways to meter that can easily differ 1 stop.

That's a very good one, thank you!
I use fresh film. All of my stock is in the fridge. The same I believe goes for the seller of these films as for years now I get very consistent results. My metering depends on the camera I use. My F100 for example gives consistent and always spot on results across an entire 135 roll, while with all manual cameras one can see when I have used a handheld meter (a minolta spot meter btw), and when I estimated the exposure and when I did that and missed it by a stop or sometimes even more.

Lachlan Young · Jan 19, 2021

Old Gregg said:
I am not asking you to distrust your own eyes If you are getting thin negatives, I do not doubt that. I only said that I had never heard of anyone consistently experiencing this. So thin HP5+ negatives with Ilford-recommended times is not a (quoting you) "commonly admitted" problem in any of the online communities I frequent.

Given the coefficients between Ilford & Kodak's recommended times/ agitation patterns, if someone is claiming 'thin' negs with Ilford's times, they're going to be even worse with Kodak's. And of course you actually want the thinnest possible neg that prints with full detail at a reasonable contrast grade in order to maximise sharpness...

pentaxuser · Jan 19, 2021

Lachlan Young said:
TMax 100 had to have an extra thick supercoat layer to slow developer diffusion because the T-grains would otherwise develop so fast as to be much less controllable than would be desirable.

Sort of suggests that Kodak could have omitted the pre-wet advice for this particular film, doesn't it or many it went to the trouble and expense of the extra thick supercoat layer to all for both pre-wet and the T-grains?

pentaxuser

138S · Jan 19, 2021

zanxion72 said:
My metering depends on the camera I use. My F100 for example gives consistent and always spot on results across an entire 135 roll, while with all manual cameras one can see when I have used a handheld meter (a minolta spot meter btw), and when I estimated the exposure and when I did that and missed it by a stop or sometimes even more.

Let me add those points better described:

> You can measure densities simply with the scanner, just scan film alongside an Stouffer T2115 density wedge to compare.

> To know if your development is on the standard contrast just check if some gray subject that has been spot metered by +2 has a density that is around 0.51D higher than an spot metered -1. As meters may have a 1/3 stop resolution better if you check the density boost from 3 additional stops range, then error in the Contrast Index calculation will be lower...

> If you want consistency between cameras/meters you don't even need to shot film, just compare the metering each device provides in front of the same scene.

> If you want to know if you are using the true speed, first adjust development to have that 0.51D increase for ecah 3 stops additional exposure, then check that an spot metered 0+/- has a 0.72D more than Base+Fog density, Base+Fog is measured in an area that has not been exposed to light.

_____

Note that the speed point is underexposed 3.33 stops and has an standard density of 0.1D over Base+Fog.

Form B+F to Speed point you have 0.1D increase, and from Speed Point to the Meter 0+/- Point you have an additional increase of 0.62D. So from B+F to the density of a 0+/- spot metered gray subject you have 0.1D + 0.62 = 0.72D.

Either you can check if an spot metered 0+/- delivers 0.72D over F+B, or if that 0+/- spot delivers 0.62D over the density of a -3.33 underexposed spot (with will be in the speed point).

_____

At all those calculations are necessary to get great images, but if one likes to do that then one may get more consistency when using different films or developers, still doing that once in a lifetime it's quite nice to feel how film works..

zanxion72 · Jan 19, 2021

138S said:
Let me add those points better described:

> You can measure densities simply with the scanner, just scan film alongside an Stouffer T2115 density wedge to compare.

> To know if your development is on the standard contrast just check if some gray subject that has been spot metered by +2 has a density that is around 0.51D higher than an spot metered -1. As meters may have a 1/3 stop resolution better if you check the density boost from 3 additional stops range, then error in the Contrast Index calculation will be lower...

> If you want consistency between cameras/meters you don't even need to shot film, just compare the metering each device provides in front of the same scene.

> If you want to know if you are using the true speed, first adjust development to have that 0.51D increase for ecah 3 stops additional exposure, then check that an spot metered 0+/- has a 0.72D more than Base+Fog density, Base+Fog is measured in an area that has not been exposed to light.

_____

Note that the speed point is underexposed 3.33 stops and has an standard density of 0.1D over Base+Fog.

Form B+F to Speed point you have 0.1D increase, and from Speed Point to the Meter 0+/- Point you have an additional increase of 0.62D. So from B+F to the density of a 0+/- spot metered gray subject you have 0.1D + 0.62 = 0.72D.

Either you can check if an spot metered 0+/- delivers 0.72D over F+B, or if that 0+/- spot delivers 0.62D over the density of a -3.33 underexposed spot (with will be in the speed point).

_____

At all those calculations are necessary to get great images, but if one likes to do that then one may get more consistency when using different films or developers, still doing that once in a lifetime it's quite nice to feel how film works..

A great thank you for this! It will certainly help me improve my workflow by quite a bit towards better and more consistent results.

Craig75 · Jan 19, 2021

OP just wants to know what to do with his one stop over exposed film and he can

1. develop it as per box instructions for iso400
or
2. cut develop by circa 10%

either will get the job done for him with slightly different results.

Sirius Glass · Jan 19, 2021

zanxion72 said:
I am not confusing anything my friend. The given time for HP5 gives a rather thin film negative. I have tested that film to more developers you can think of (135 and Medium Format only), commercial and home brew.My preferred rating, if you don't like the term true speed, in ID11/D76 is EI 320 and EI 200 is not far from it.
Btw, my preferred normal agitation scheme is 5 inversions/rotations (lasting 10") every minute. I never liked the results of Kodak's suggested agitation scheme.

Old Gregg said:
I am not asking you to distrust your own eyes If you are getting thin negatives, I do not doubt that. I only said that I had never heard of anyone consistently experiencing this. So thin HP5+ negatives with Ilford-recommended times is not a (quoting you) "commonly admitted" problem in any of the online communities I frequent.

If one film or one developer produced thin films, then that is a product issue. If everyone else is out of step with you and they are also synchronized then there is a systematic problem you have and you should work out what is wrong with what you are doing. Are you timing the development time correctly? The development start time and stop stop should be at the same point. Look at what you are doing. The world is not wrong, you are making a consistent mistake. Have you had ALL of your light meters calibrated by a calibration expert, not yourself?

Lachlan Young · Jan 19, 2021

Sirius Glass said:
If one film or one developer produced thin films, then that is a product issue. If everyone else is out of step with you and they are also synchronized then there is a systematic problem you have and you should work out what is wrong with what you are doing.

It's quite likely related to whatever developer he's using - and how long the bottle's been open/ time since stock solution was mixed. I never cease to be amazed at how often this turns out to be the cause of so many partial failures in processing.

Sirius Glass · Jan 19, 2021

michael_r said:
I’m still not clear on rationale for option 2. Why attempt to “compensate” for increased exposure by reducing contrast?

We agree. Option 2 undoes the increased exposure. Open one stop and develop normally.

138S · Jan 19, 2021

michael_r said:
I’m still not clear on rationale for option 2. Why attempt to “compensate” for increased exposure by reducing contrast?

I agree, usually it would not may make much sense. Still, if we have extreme highlights in the scene then reducing contrast may prevent blowing those extreme highlights.

138S · Jan 19, 2021

michael_r said:
That’s a misconception.

If we compare two bracketed (0 and +1) shots, in the +1 shot all spots in the frame that are in the linear zone will result with its density increased by 0.17D. Spots that were at +5 will be at +6, so (suposing 0.15D for F+B) density is to move from 1.7D to 1.9D.

This is what it would happen with densities... No problem if scanning... but... the question is if that 1.9D may be more problematic to be printed in the darkroom !! And... are we moving areas from the linear zones to the shoulder ?

HP5 Overexpose / Underdevelop Question

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